Technical Sciences Grade 12 P2 Gauteng Mock 2020 Memo (Afr)

PREPARATORY EXAMINATION VOORBEREIDENDE EKSAMEN 2020 MARKING GUIDELINES/NASIENRIGLYNE TECHNICAL SCIENCES/TEGNIESE WETENSKAPPE (PAPER/VRAESTEL 2) 11102 12 pages/bladsye . 1

11102/20 QUESTION/VRAAG 1 1.1 A  (2) 1.2 C  (2) 1.3 A  (2) 1.4 A  (2) 1.5 B  (2) 1.6 A  (2) 1.7 B  (2) 1.8 B  (2) 1.9 C  (2) 1.10 D  (2) [20] 2

11102/20 QUESTION/VRAAG 2 2. 1 A series of organic compounds that can be described by the same general formula and where each member differs from the next by a CH2 group.  (2) ʼn Reeks organiese verbindings wat deur dieselfde algemene formule beskryf word. Die lede in die reeks verskil van mekaar met ʼn CH 2-groep.  2.2.1 A (1) 2.2.2 D (1) 2.3.1 1-bromo-2-methylpropane  (2) 1-bromo-2-metielpropaan  2.3.2 2,5-dimethylhexane  (2) 2,5-dimetielheksaan  2.3.3 Methanoic acid  (2) Metanoësuur 2.4.1  (2) 2.4.2 CnH2n  (2) 2.5.1 Haloalkanes/alkyl halides  (1) Haloalkane/alkielhaliede  2.5.2 Alcohols  (1) Alkohole 2.6 Small organic molecules that can be covalently bonded to each other in a repeating pattern  Klein organiese molekule wat in herhaalde patrone kovalent met mekaar verbind  (2) [18] 3

11102/20 QUESTION/VRAAG 3 3.1 The pressure exerted by a vapour at equilibrium with its liquid ✓in a closed system ✓ (2) In ʼn geslote sisteem is ✓druk uitgeoefen deur die damp van ʼn stof in dinamiese ewewig met die vloeistof ✓ 3.2 London/dispersion forces ✓ (1) London/dispersie kragte ✓ 3.3 All organic molecules in the table consist of weak London forces. - Boiling point decreases with a decrease in the chain length (surface area). ✓ - The lower the boiling point the weaker the intermolecular forces. ✓ - Less energy is required to overcome intermolecular forces. ✓ OR - Boiling point increases with an increase in the chain length surface area). ✓ - The higher the boiling point, the stronger the intermolecular forces. ✓ - More energy is required to overcome intermolecular forces. ✓ (3) Alle organiese molekule in die table bestaan uit swak London kragte. - Kookpunt neem af met ʼn afname in ketting lengte (kontakoppervlakte). ✓ - Hoe laer die kookpunt, hoe swakker die intermolekulêre kragte. ✓ - Minder energie is nodig om intermolekulêre kragte te oorkom. ✓ OF - Kookpunt neem toe met ʼn toename in kettinglengte (kontakoppervlakte).✓ - Hoe hoër die kookpunt, hoe sterker die intermolekulêre kragte. ✓ - Meer energie is nodig om intermolekulêre kragte te oorkom. ✓ 3.4 Boiling point increases with a decrease in vapour pressure ✓✓ (2) Kookpunt neem toe met n afname in dampdruk. ✓✓ 3.5.1 Viscosity ✓ (1) Viskositeit ✓ 3.5.2 Syrup is denser than water✓ therefore it has stronger intermolecular forces than water.✓ The stronger the intermolecular forces, the higher the viscosity.✓ (3) Stroop is digter as water✓ daarom het dit sterker intermolekulêre kragte.✓ Hoe sterker die intermolekulêre kragte hoe hoër die viskositeit.✓ [12] 4

11102/20 QUESTION/VRAAG 4 4.1 2C2H2 + 3O2 → 2CO2 + 2H2O (reactants) ✓ (products) ✓ (balancing) ✓ (3) 2C2H2 + 3O2 → 2CO2 + 2H2O (reaktante) ✓ (produkte) ✓ (balansering) ✓ 4.2.1 Propane ✓✓/Propaan✓✓ (2) 4.2.2 1-chloropropane ✓✓/1-chloropropaan ✓✓ (2) 4.3.1 Hydrogenation✓/Hidrogenasie✓/Hidrogenering✓ (1) 4.3.2 Hydration ✓/Hidrasie✓ (1) 4.3.3 Halogenation ✓/Halogenasie✓ (1) 4.3.4 Hydrohagenation ✓/Hidrohalogenasie✓ (1) 4.4.1 ✓ ✓ ✓ (3) 4.4.2 ✓ ✓ ✓ (3) [17] 5

11102/20 QUESTION/VRAAG 5 5.1 From chemical to electrical energy ✓✓ (2) Van chemiese na elektriese energie✓✓ 5.2 A✓ (1) 5.3 Hydrogen gas/H2 ✓✓ (2) Waterstofgas/H2 ✓✓ 5.4.1 O2(g) +4H++ 4e− →2H2O(g)  (2) 5.4.2 2H2(g) +O2(g) →2H2O  Award 2/3 if: 2H2(g) + 4H+ +O2(g)→ 2H2O + 4H+ (3) 5.4.3 OPTION/OPSIE 1: OPTION/OPSIE 2: EƟcell = EƟreduction - EƟoxidation  H2→ 2H+ + 2e- 0,00 V  EƟsel = EƟreduksie - EƟoksidasie O2 + 4H++ 4e- → 2H2O  = 1,26  - (0)  + 1,26  = 1,26 V  H2 + O2 → H2O 1,26 V  (4) 5.5 Temperature/Temperatuur = 298 K/25 °C ✓ Pressure/Druk= 100 Kpa/1,01 x 105 Pa ✓ Concentration/Konsentrasie = 1 mol.dm-3 ✓ (3) [17] 6

11102/20 QUESTION/VRAAG 6 6.1 An electrochemical cell that converts electrical energy to chemical energy ✓✓ (2) ʼn Elektrochemiese sel wat elektriese energie omskakel na chemise energie ✓✓ 6.2.1 Closed switch/Geslote skakelaar /Kragbron of Battery Gold electrode/Goud /Metaallepel elektrode /Goud elektroliet Marking Criteria/Nasienriglyne Marks/ Punte Gold electrolyte connected to the positive terminal of the power ✓ source Goud elektroliet gekoppel aan positiewe terminaal van battery Metal spoon connected to the negative terminal of the power ✓ source Metaallepel gekoppel aan negatiewe terminaal van battery Closed switch/Geslote skakelaar ✓ Gold electrolyte indicated in the solution ✓ Goud elektroliet in die oplossing Power source correctly connected ✓ Kragbron reg gekoppel Only one container with electrolyte used ✓ Slegs een houer met elektroliet is gebruik (6) 6.2.2 Spontaneous ✓/Spontaan✓ (1) 6.2.3 The reaction will not occur on its own unless the cell is connected to a power source. ✓✓ (2) Die reaksie sal nie vanself gebeur, voordat ʼn sel gekoppel is aan ʼn kragbron nie.✓✓ 6.2.4 Gold electrode ✓/Goud elektrode ✓✓ (1) 7

11102/20 6.2.5 The gold electrode is the reducing agent/undergoes oxidation therefore it donates electrons to the solution. ✓ Die goud elektrode is die reduseermiddel/ondergaan oksidasie gee dus elektrone af ✓ The gold ions in the gold solution accept the electrons and form a deposit around the spoon. ✓ Die goud ione in die goud oplossing neem die elektrode op en vorm ʼn goudlaag rondop die lepel.✓ (2) 6.2.6 It enhances the look of gold plated material. ✓ Dit verbeter die voorkoms van goud plateerde items ✓ It is less expensive than the original gold. ✓ Goedkoper as oorspronklike goud ✓ (2) , 6.3.1 - The fuel cell not only does not create pollution ✓ Brandstof veroorsaak geen besoedeling nie ✓ - It also makes a by-product that in some environments is a valuable commodity (water). ✓ ʼn Byproduk, naamlik water word geproduseer, wat in sekere omgewings bruikbaar is ✓ - Conventional batteries used in fuel cars are heavy and expensive to replace. Batterey wat gebruik word is baie swaar en duur om te vervang ✓ Any TWO/enige TWEE (2) [18] 8

11102/20 QUESTION/VRAAG 7 7.1.1 (When a light ray is incident on a plane surface,) the incident ray, the reflected ray and the normal (to the surface) lie in the same plane✓ and the angle of incidence is equal to the angle of reflection. ✓ (2) (Waneer in ligstraal inval op ʼn plat vlak), is die invallende straal geweerkaatste straal en die normaal (op die oppervlak) in dieselfde plat vlak✓ Die weerkaatsingshoek is gelyk aan die invalshoek ✓ 7.2 • virtual ✓/Skyn ✓ • erect/upright ✓/Regop✓ • the same size as the object ✓/dieselfde grootte as voorwerp✓ • the same distance from the mirror as the object’s distance/vanaf die spieël as die voorwerp ✓ Any THREE/Enige DRIE (3) 7.3 virtual ✓/Skyn✓ (1) 7.4.1 • A ray of light must move from a medium with high optical density to a medium of low optical density./Ligstraal moet beweeg van ʼn medium met hoë optiese digtheid na ʼn medium met laer optiese digtheid. • Angle of incidence must be greater than the critical angle. /Invalshoek moet groter wees as kritiese hoek. (2) 7.4.2 Binoculars /Verkykers Telescopes /Teleskope Endoscope/Endoskoop Periscope/Periskoop Fibre optic light/Optiese vesel lig Any TWO/Enige TWEE (2) 9

11102/20 7.4.3 Less dense medium/Minder opties dig Normal/Normaal More dense medium/ Meer opties dig 50° 50° Incident ray /Invallendestraal Reflected ray/Geweerkaatste Straal Marking Criteria/Nasienriglyne Marks/Punte Direction of both rays (incidence ray and reflected ray) indicated correctly and rays are in the same medium ✓ (water)/Beide hoeke (invals en geweerkaatste) is gelyk Both angles (angles of incidence and reflected angle) ✓ equal/Rigting van beide strale (invallende en geweerkaatste) reg aan gedui en strale in dieselfde medium (water). Incident ray correctly labelled/Invalstraal, korrek benoem. ✓ Reflected ray correctly labelled/Geweerkaatste straal , ✓ benoem Normal/Normaal ✓ (5) [15] 10

11102/20 QUESTION/VRAAG 8 8.1.1 Refraction /Refraksie  (1) 8.1.2 In glass A the pencil is entering the water perpendicular to the water therefore its image in the water goes straight through/does not get refracted.  In glas A is die potlood loodreg in die water, daarom is die beeld in die water reguit/word nie gebreek nie  In glass B the pencil enters the water at an angle therefore its image in the water gets refracted/bends/looks broken. / In glas B is die potlood met ʼn hoek in die water, daarom lyk die beeld gebuig/gebroke (4) 8.2.1 Dispersion /Dispersie (1) 8.2.2 The phenomenon whereby white light breaks up into its component colours.  Die verskynsel waar wit lig opbreek in sy samestellende kleure.  (2) 8.2.3 Red , Orange , Yellow , Green , Blue , Indigo , Violet Rooi, Oranje, Geel, Groen, Blou, Indigo, Violet. (7) [15] QUESTION/VRAAG 9 9.1 Concave lens /Konkawe lens Convex lens /Konvekslens (2) 9.2 Hyperopia/far-sightedness /Versienheid (1) 9.3 Convex/converging lens /Konveks/konvergerende lens.  (1) 9.4 Myopia/short-sightedness /Nabysienheid (1) 9.5 Concave/diverging lens /Konkawe/divergerende lens (1) [6] 11

11102/20 QUESTION 10/VRAAG 10 10.1 A changing magnetic and electric field mutually perpendicular to each other and in the direction of propagation of the wave  ʼn Verandering van n magnetise en ʼn elektriese veld loodreg tot mekaar en tot die rigting van die voortplanting van die golf  (2) 10.2 A – Gamma rays /Gamma strale  B – Ultra violet light /Ultraviolet strale  C – X-rays /X-strale (3) 10.3.1 A quantum of energy / ʼn kwantum van energie (2) 10.3.2 c = f  3,00 x 108 = f(4,06 x 10-11 )  = 7,34 x 1019 E=hc = 6,63 x 10-34 x 7,34 x 1019  = 4,90 × 10-15 J  (5) [12] TOTAL/TOTAAL: 150 12